how can I do 3D Interpolation from 2D images?

I have 20 2D images (.png) which I should do 3D interpolation to have one 3D image. my problem is that i'm confused of the formats, and using command "interp3" anybody can help me about it?

thanks in advance

[Walter Roberson]

The interpolation you are doing: does that have to do with stereo projection?

[moein Pakdel sefidi]

I don't know what is really stereo projection, it's from PIV measurement.

Images are like this